Release date: September 21, 1994[ citation needed ]
Current version: 3.50.807 SP3 (June 21, 1995)[ citation needed ]
Source model: Closed source
License : Microsoft EULA
Kernel type: Hybrid kernel
Windows NT 3.5 is the second release of the Microsoft Windows NT operating system . It was released on September 21, 1994. One of the primary goals during Windows NT 3.5's development was to increase the speed of the operating system; as a result, the project was given the codename "Daytona" in reference to the Daytona International Speedway in Daytona Beach, Florida .  This is the first Windows NT to adopt the names Windows NT Workstation and Windows NT Server for its editions. The editions of the previous Windows NT release, Windows NT 3.1 , were named Windows NT and Windows NT Advanced Server .
New features in Windows NT 3.5 include the new startup screen. The interface was updated to be consistent with the Windows for Workgroups 3.xx . It also upgraded Object Linking and Embedding (OLE) support from version 1.0 to version 2.0 and is more efficient - performance is higher and it requires less memory than Windows NT 3.1.
In July 1995, Windows NT 3.5 with Service Pack 3 was rated by the National Security Agency as complying with TCSEC C2 criteria.
Windows NT 3.5 refuses to install on a processor newer than the original Pentium (P5 core).  Windows NT 3.51 fixed this. It is however possible to modify files on the install CD which will allow it to install.
Windows NT 3.51 is the third release of Microsoft 's Windows NT line of operating systems . It was released on May 30 , 1995 , nine months after Windows NT 3.5 . The release provided two notable feature improvements; firstly NT 3.51 was the first of a short-lived outing of Microsoft Windows on the PowerPC CPU architecture. The second most significant enhancement offered through the release was that it provides client /server support for interoperating with Windows 95 , which was released three months after NT 3.51. Windows NT 4.0 became its successor a year later; Microsoft continued to support 3.51 until December 31 , 2001 .
Windows NT 3.51
The release of Windows NT 3.51 was dubbed "the PowerPC release" at Microsoft. The original intention was to release a PowerPC edition of NT 3.5, but according to Microsoft's David Thompson, "we basically sat around for 9 months fixing bugs while we waited for IBM to finish the Power PC hardware". Editions of NT 3.51 were also released for Intel 's x86 , MIPS , and DEC Alpha architectures.
Despite the significant difference in the kernel base, Windows NT 3.51 is readily able to run a large number of Win32 applications designed for Windows 95 . Most recent 32-bit applications will not work as the developers have prevented their application from working with any Windows version earlier than Windows 98, also because some applications do not work properly with the older Windows NT 3.51 interface. Despite this, Microsoft in their application releases muddied the issue, releasing 32-bit versions of Microsoft Office right up to Office 97 SR2b, but relying upon 16-bit versions of Internet Explorer technology. This is probably because 32-bit versions of Internet Explorer 4.0 and later integrated with the Windows 95 desktop, and NT 3.51 still used the Windows 3.1 desktop. Later on, up to IE 5.0 , but not later 5.x versions, were offered.
Microsoft also released test versions of a shell refresh, named the Shell Technology Preview , and often referred to informally as "NewShell". The update was designed to replace the Windows 3.x Program Manager/File Manager based shell with a Windows Explorer -based graphical user interface . The release provided capabilities quite similar to that of the Windows "Chicago" ( codename for Windows 95) shell during its late beta phases, however was intended to be nothing more than a test release. There were two public releases of the Shell Technology Preview, made available to MSDN and CompuServe users; May 26 , 1995 and August 8 , 1995 . Both held Windows Explorer builds of 3.51.1053.1. The Shell Technology Preview program never saw a final release under NT 3.51. The entire program was moved across to the Cairo development group who finally integrated the new shell design into the NT code with the release of NT 4.0 in July 1996.
Five Service Packs were released for NT 3.51, which introduced both bug fixes and new features. Service Pack 5, for example, fixed issues related to the Year 2000 problem .
NT 3.51 was the last of the series to run on a Intel 80386 processor. This, its ability to use HPFS partitions (which Windows 2000 and later could not), and its ability to run at least some of the common control API, means that it still finds a place for occasional use on older machines.
Hardware requirements 90 MB 90 MB Hard disk drive free space VGA video VGA video Video 16 MB RAM 12 MB RAM Memory 386 or 486/25 processor 386 or 486/25 processor Processor "Windows NT Server" "Windows NT Workstation" Windows NT 3.51 hardware requirements
Hybrid kernel Kernel type Microsoft EULA License Closed source Source model 3.51.1057 SP5 ( September 19 , 1996 ) [ citation needed ] Current version May 30 , 1995 [ citation needed ] Release date Releases Microsoft Developer Windows NT 3.51 running Microsoft Excel 97